The present invention addresses the problem of the control of variable-ratio transmissions.
A typical example of a transmission of this type, which will be referred to for simplicity in the following description, is that of a bicycle transmissions. In this connection, a method and a device for automatically controlling the transmission ratio of a bicycle so as automatically to identify the optimal ratio in dependence on the pedalling effort or force are known from EP-A-0 831 021.
The same subject is addressed in various other patent documents such as, for example, U.S. Pat. Nos. 5,059,158, 5,538,477, 5,356,348, 5,569,104 and 5,728,017, in which it can be seen that the control may be exerted either on the rear derailer or on the front derailer, or on both derailers of a sports cycle.
The object of the present invention is to improve systems for controlling the ratio in variable-ratio transmissions, particularly with regard to the optimization of the interaction between an apparatus having such a transmission and an operator using the apparatus.
According to the present invention, this object is achieved by means of a system having the specific characteristics recited in the following claims. The invention also relates to the respective method of operation.
The application of the intention if particularly advantageous in the cycling field and, in particular, in the field of competitive cycling.